Motors are widely used in many fields such as CD-ROM or DC motor. In general, a shaft of motor is confined by a retaining ring to prevent the shaft from being displaced in an axial direction. FIG. 1A is a sectional view of the traditional assemblage for confining a shaft of the motor. The assemblage includes a bushing 12, a bearing 11, a shaft 10, and a retaining ring 13. A bushing cover 15 with an external screw thread is disposed in the bottom of bushing 12. The bushing 12 is used to accommodate therein the bearing 11, the shaft 10, and the retaining ring 13. A washer 14 supporting the shaft 10 is disposed on the bushing cover 15. FIG. 1B is a top view of the retaining ring 13 which is an annular plate structure having a gap 131. Because the retaining ring 13 has the gap 131 and a flexibility, the retaining ring 13 must be opened by an external force, thereby an end 102 of shaft 10 will pass through a hollow portion of the retaining ring 13 and a recess 101 of the shaft 10 will be confined by the retaining ring 13 while the end 102 passes through the hollow portion. The shaft 10 is tightly fastened by the retaining ring 13.
However, such a retaining ring still brings about the inconvenience of the assembling process and thus it is desired to modify the design of the retaining ring. The altitude of the shaft is adjusted by the bushing cover 15. If the bushing cover is not closed hermetically, the leakage of lubricant will happen. Furthermore, the altitude of the shaft can not be easily controlled.
Therefore, the present invention provides a practical device and its relative assemblage for obviating the disadvantage of the prior arts as described above.